Wilmot said the 15 buses the district owns were affected. Most of the tires had been repaired by Monday afternoon.

Lisbon Police Chief David Brooks said the department had received many possible leads through social media.

"We are investigating. My resource officers and a detective are looking into it as we speak and I hope that eventually we will come to a conclusion here and find the individual or individuals involved," he said.

Forty years ago, one of the greatest boxing matches in history took place in an unlikely setting: the capital of the Philippines. Muhammad Ali's epic win over great rival Joe Frazier in 1975 became known as the "Thrilla in Manila."